Biosensors & Bioelectronics

High Throughput Optical Biosensor for Monitoring Pb (II) Ions in Milk through Fluorescence based Microarray Approach

Abstract

Hardeep K* and Verma N

Milk is a bulk consumer product therefore it serves a versatile source of public exposure to contaminants. Among the various heavy metals, lead has been recognized as the leading environmental health threat and milk has been found mostly contaminated with high levels of Pb (II) ions. In present study an optical biosensor is developed employing Bacillus sphaericus (MTCC 5100) as biorecognition unit and the analysis is based on urease inhibition resulting in fluorescence change. Investigation was carried out by means of fluorescence dye (Rhodamine 6G) in hydrophobic environment with the heavy metal. The novelty of the method lies in the formula that is devised to detect equivalent Pb (II) ions in milk in the presence of Cd (II). Lowest detection limit achieved is 0.48 nM Pb (II) equivalents in spiked milk samples (permissible limit 96.6 nM). This is the first report on low level Pb (II) monitoring in milk through high throughput microarray biosensing.